A next generation streetcar system is a next generation track transportation system. In the next generation streetcar system, radio communication is performed between a mobile station provided in a train and base stations provided along a track. In this case, multiple base stations are provided along the track. Therefore, when the train travels along the track, the mobile stations continuously perform communication by performing handover for, for example, a base station having the best radio wave reception state among the plurality of base stations.
When there is a structure such as a station building or a tall building between the track and the base station, since a radio wave reception state on the train rapidly deteriorates due to the influence of shadowing, there is a case in which communication is interrupted. For example, when communication is interrupted for several seconds, it is probable that a critical problem such as frame drop or frame freeze occurs in image transmission and the like in which real-time property is required.
Various technologies associated with such a background have been known (for example, refer to Patent Literature 1).
For example, Patent Literature 1 discloses a wireless train control system in a railway security system, which performs switching operation for a ground-based wireless transmission apparatus when a train moves during communication. In more detail, in the train control system, a handover point, which is a point at which an on-board wireless transmission apparatus changes the ground-based wireless transmission apparatus serving as a communication destination, is stored in a ground control apparatus. The train control system determines whether the train approaches the handover point based on position information transmitted by the train. When the train control system determines that the train approaches the handover point, the train control system reserves in advance a communication channel for communicating with the ground-based wireless transmission apparatus serving as the next communication destination of the train in communication with the ground control apparatus. In this way, according to the train control system, it is possible to reliably reserve a communication channel regardless of the influence of a change in the strength and the like of a radio wave due to a peripheral environment.